US5594076A - Hydrodegradable polyesters - Google Patents

Hydrodegradable polyesters Download PDF

Info

Publication number
US5594076A
US5594076A US08485162 US48516295A US5594076A US 5594076 A US5594076 A US 5594076A US 08485162 US08485162 US 08485162 US 48516295 A US48516295 A US 48516295A US 5594076 A US5594076 A US 5594076A
Authority
US
Grant status
Grant
Patent type
Prior art keywords
copolymer
hydrodegradable
ch
polyester
polyesters
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Expired - Fee Related
Application number
US08485162
Inventor
Bernard Gordon, III
Prabodh P. Sharma
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Penn State Research Foundation
Original Assignee
Penn State Research Foundation
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Grant date

Links

Images

Classifications

    • CCHEMISTRY; METALLURGY
    • C08ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
    • C08GMACROMOLECULAR COMPOUNDS OBTAINED OTHERWISE THAN BY REACTIONS ONLY INVOLVING UNSATURATED CARBON-TO-CARBON BONDS
    • C08G63/00Macromolecular compounds obtained by reactions forming a carboxylic ester link in the main chain of the macromolecule
    • C08G63/02Polyesters derived from hydroxycarboxylic acids or from polycarboxylic acids and polyhydroxy compounds
    • C08G63/12Polyesters derived from hydroxycarboxylic acids or from polycarboxylic acids and polyhydroxy compounds derived from polycarboxylic acids and polyhydroxy compounds
    • C08G63/16Dicarboxylic acids and dihydroxy compounds
    • C08G63/18Dicarboxylic acids and dihydroxy compounds the acids or hydroxy compounds containing carbocyclic rings
    • C08G63/181Acids containing aromatic rings
    • C08G63/183Terephthalic acids
    • YGENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y10TECHNICAL SUBJECTS COVERED BY FORMER USPC
    • Y10STECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y10S525/00Synthetic resins or natural rubbers -- part of the class 520 series
    • Y10S525/938Polymer degradation

Abstract

Hydrodegradable polyesters based upon the random copolymerization of aromatic and absorbable aliphatic polyesters are disclosed. The hydrodegradable polyesters are useful in preparing a variety of products including disposable containers, disposable diapers, fishing lines and nets, and the like.

Description

This is a continuation of U.S. application No. 08/135,035, filed Oct. 12, 1993, abandoned, which is a continuation-in-part of U.S. application No. 08/060,763, filed May 11, 1993, abandoned, and a continuation-in-part of U.S. application No. 07/764,652, filed Sep. 24, 1991, abandoned, U.S. application No. 08/060,763 being a continuation of U.S. application No. 07/764,652, which latter application is a continuation of U.S. application No. 07/391,894, filed Aug. 10, 1989, abandoned.

FIELD OF THE INVENTION

The present invention is concerned with providing hydrodegradable polyesters and products made therewith.

BACKGROUND OF THE INVENTION

Products made from polymeric materials have become a major environmental concern due to the difficulty in disposing of the spent products. The advantage of utilizing polymeric materials having infinite lifetimes to manufacture such items as disposable containers, fishing lines and nets, and disposable diapers has become an increasing environmental concern when these items are indiscriminately discarded into the environment. One solution proposed for reducing plastic wastes from these spent items is to design new polymers, or modify existing polymers, such that these newly developed plastics undergo degradation once the useful lifetime of the product is over and they are discarded.

Polymers may be made to degrade as they are continually used or after they are disposed by several different mechanisms. However, while each mechanism has its own advantages, each also has its faults.

Polymers may be made to degrade by photochemical means, for example. Thus, when the polymer is exposed to sunlight over protracted periods, it undergoes certain chemical changes resulting in its degradation. These polymers have a serious fault, however, in that the polymer will not degrade if the item is not exposed to the correct wavelength of sunlight. Thus, if the items made from a photodegradable polymer are discarded in a land fill, they will be buried, sunlight will not be able to reach the polymer, and degradation will not take place. Recycling of these materials is also difficult; there is no way of knowing how much degradation has occurred and the resulting new end groups on the polymer are ill defined.

Polymers may also be made to degrade by microbial means as well. Two such polymers are polycaprolactone (which is not a polymer of choice for many applications because of its poor overall physical characteristics) and blended polymers containing a enzymatic digestible component. One example of such a blended material is polyethylene which has mixed therewith an enzymatically degradable starch. When this polymer is discarded, enzymes produced by various bacterial and fungal species will attack the starch portions of the blended material, digesting it and leaving a very porous polyethylene residue which, unfortunately, stays in the environment.

Although aliphatic polyesters are well known to degrade by hydrolysis, aromatic polyesters that are commonly used for fibers and molded articles have been shown to undergo little, if any, degradation. A number of degradable polymers have received patents in the United States. For example, Stager and Minor have obtained U.S. Pat. No. 3,647,111 for a biodegradable soft drink can; Henry has obtained U.S. Pat. No. 3,676,401 for a photodegradable polyethylene film; Schmitt et al., have obtained U.S. Pat. No. 3,784,585 for water degradable resins containing blocks of polyglycolic acid units; Brackman has obtained U.S. Pat. No. 3,840,512 for degradable polyethylene; Guillet and Dan have obtained U.S. Pat. No. 3,878,169 for a photodegradable polyester; Coquard et al., have obtained U.S. Pat. No. 4,032,993 for implantable surgical articles which are bioresorbable and contain a copolyester of succinic acid and oxalic acid; and Yamamori et al., have obtained U.S. Pat. No. 4,482,701 for hydrolyzable polyester resins which contain therein a metallic salt of a hydroxy carboxylic acid.

In general, polyesters and copolyesters, as well as the preparation of these polymers, are described in both the scientific and patent literature. Carothers et al [Journal of the American Chemical Society 52:3292 (1930)], for example, describes the ester interchange reaction of various diols (such as ethylene glycol or 1.4-butanediol) and diesters to yield polymer. The preparation of polyesters of fiber-forming quality from dicarboxylic acids and diols is described in U.S. Pat. No. 2,952,652.

SUMMARY OF THE INVENTION

We have now discovered that copolyesters of aromatic and aliphatic types can be made to degrade over a period of time and with exposure to water, under hydrolytic conditions. Thus, commercially used aromatic polyesters, and products made therefrom, can be made to degrade after expiration of their useful lifetime by randomly incorporating a hydrodegradable segment into the polymer backbone by conventional copolymerization or transesterification of the reactant monomers. Depending upon the aliphatic comonomer and the amount used in the manufacture of the final polymer, the time for the loss of the physical properties of the polymer can be adjusted and thus degradation controlled. An additional advantage of the polymers according to the present invention is that the hydrolytic degradation cleanly forms oligomers with acid and alcohol end groups. The degraded material could then be recycled by the repolymerization of these new end groups.

Prior to our invention, there was little appreciation or recognition in the prior art of the hydrolysis of a copolymer containing mostly aromatic polyester units. In particular, there has been no suggestion of manufacturing environmentally degradable aromatic polyesters by the inclusion of aliphatic links susceptible to hydrolysis.

The copolymer formulations according to this present invention are degradable polyesters made from aromatic and aliphatic polyester moieties. Depending upon the amount and type of aliphatic unit used in the formulation of these copolymers, the resultant copolymers, and products made therefrom, will have varied (but limited) lifetimes upon exposure to water before they degrade. The environmentally degradable copolymers according to the present invention are of particular value for polymer articles and fibers that are routinely discarded after use. Exemplary of such articles are fishing lines, fishing nets, disposable containers, disposable diapers, and the like.

DETAILED DESCRIPTION OF THE INVENTION

In general, the copolymers of the present invention contain therein a moiety selected from the group consisting of: ##STR1## wherein

R is selected from the group consisting of a straight or branched alkylene moiety of 2 to 16 carbons (most preferably an alkylene moiety of 2 to 4 carbons) in length, a polyether of the formula --[(CH2)n --O--]x --(CH2)n --, and mixtures thereof, wherein n is a number from 2 to 16, X is 1 to 1000 (most preferably 10 to 1000);

R1 is hydrogen or a lower straight or branched alkyl moiety of 1 to 10 carbons in length;

R2 is selected from the group consisting of a straight or branched alkylene moiety of 2 to 16 carbons (most preferably an alkylene moiety of 2 to 4 carbons) in length, a polyether of the formula --[(CH2)n --O--]x --(CH2)n --, and mixtures thereof, wherein n is a number from 2 to 16, X is 1 to 1000 (most preferably 10 to 1000);

R3 is a straight or branched alkyl moiety of 0 to 40 carbons, most preferably a straight moiety of 0 or 4 carbons or a branched moiety of 22 carbons; and

with the proviso that said hydrodegradable random polyester copolymer does not contain therein a hydroxy metal salt of a carboxylic acid.

More specifically, the random copolymers of the present invention are comprised of a polyester polymer such as, for example, polyethylene teraphthalate; polybutylene teraphthalate; polyarlyates such as poly bisphenol-A teraphthalate; aliphatic polyester blocks in polyurethane block copolymers; polycarbonates; the polyester portion of polyether polyester segmented block copolymer thermoplastic elastomers; and ester or alcohol terminated telechelic polymers. The polyester polymer is randomly interrupted with a hydrodegradable segment such as polyhydroxy acids like polyglycolic acid, polylactic acid, polycaprolactone, polyhydroxy butyrate, and polyhydroxy valerate; polyaliphatic esters such as polybutylene oxalate and polyethylene adipate; polyalkyl anhydrides; polyalkyl carbonates such as polyethylene carbonate and polybutylene carbonates; and polyesters containing silyl ethers, acetals, or ketals.

The random copolymers of the present invention are conveniently prepared by either ester interchange reaction between the appropriate alkylene diol, diester and ester alcohol or appropriate dimer: or by transesterification reactions of the two homopolymers with the appropriate transesterification catalysts above the melting point of the two polymers.

In general, a copolymer according to the present invention may be prepared by the transesterification of two homopolymers. An example of such a transesterification is the modification of a known polyester, polybutylene terephthalate (PBT), with polyglycolic acid (PGA) according to the following reaction scheme. ##STR2##

Other methods may be used to prepare copolymers according to the present invention. For example, copolymers may be prepared from the monomer according to the following reaction scheme. ##STR3## wherein R is hydrogen and X is 4.

In addition, a number of monomers may be substituted in this reaction. For example, polyethylene terephthalate or PET could be used in this reaction sequence by changing the polymer in transesterification or by changing the value of X to 2.

The hydrodegradable segments in the copolymers according to the present invention may be other than an oxalate moiety, as shown above. For example, the hydrolyzable moiety which becomes the hydrodegradable segment in the copolymer may be a lactide or larger alkyl moiety. Other possible alternatives for use as the hydrodegradable segments in the copolymer according to the present invention are adipate, p-dioxanone, 1,3-dioxan-2-one, caprolactone, siloxane, and anhydride moieties. These additional hydrolyzable linking segments can be used as homopolymers for transesterification (or as monomers) according to the following reaction scheme. ##STR4##

A more thorough understanding of the process for making the random copolymers of the present invention may be obtained from the following examples which utilize polybutylene terephthalate, polyglycolic acid (PGA) and polytetramethylene oxalate (PO) as homopolymers. The transesterification reaction carried out under the conditions detailed in Example I yielded a copolymer containing PBT:PGA in the rations of 90:10 and 95:5 (weight per cent).

EXAMPLE I

The reaction flask in which the copolymer was to be prepared was dried thoroughly and flushed with an inert gas. The following reaction mixture was then added to the flask and the flask heated to 235° C. under vacuum (2-4 mm. Hg) for 2 hours.

4.5 g polybutylene terephthalate

0.5 g polyglycolic acid

0.1-0.2 ml stannous octoate catalyst (0.33M solution in dry toluene: 0.3-0.5% by weight of PBT)

The reaction mixture attained a tan brown color and was allowed to cool to room temperature under an atmosphere of nitrogen. It was then crushed and purified by heating with ethyl acetate under reflux for 20 minutes. The intrinsic viscosity of the resulting copolymer was determined to be about 0.95 dl/g.

Preparation of the 95:5 copolymer was accomplished by taking PBT and PGA in the appropriate ratios and following the same procedure as described above for the 90:10 copolymer above. The intrinsic viscosity of this copolymer was found to be about 0.95 dl/g.

The preparation of polybutylene terephthalate-copolytetramethylene oxalate was carried out in accordance with Example II. The resulting PBT-PTMO copolymer was prepared in the ratios of 90:10 and 70: 30 (weight percent).

EXAMPLE II

The reaction flask in which the copolymer was to be prepared was dried thoroughly and flushed with an inert gas. The following reaction mixture was then added to the flask and the flask heated to 235°-240° C. under vacuum (2-4 mm Hg) for 2 hours.

45 g polybutylene terephthalate

5 g polytetramethylene oxalate

0.1-0.2 ml stannous octoate catalyst (0.33M solution in dry toluene)

The mixture attained a tan brown color and was allowed to cool to room temperature under an atmosphere of nitrogen. It was then crushed to a fine powder and the intrinsic viscosity of the copolymer was determined to be about 1.08 dl/g.

Preparation of the 70:30 copolymer was carried out by taking the PBT and PTMO in the appropriate ratios and following the procedure as described for the 90:10 copolymer above. The intrinsic viscosity of this copolymer was found to be about 1.1 dl/g.

The copolymers produced by Examples I and II were characterized by NMR using a Bruker 200 MHz instrument (80:20 V:V mixture of deuterated chloroform and deuterated trifluoroacetic acid as the solvent). Thermal analysis of the samples was carried out in a Perkin-Elmer 7 series Differential Scanning Calorimeter. Hydrolysis of the copolymers was followed by viscometry using a Cannon-Ubblehode viscometer and a 3/5 (V/V) phenol and tetrachloroethane solvent maintained at 3° C., 33° C., and 50° C.

NMR studies of the PBT-PGA polymer indicated that the polymer obtained is a true copolymer and not a blend. The methylene absorption of the copolymer was seen at five individual peaks between 4.8 and 5.38 as would be expected from the random to blocky placement of the glycolide repeat units along the PBT backbone.

Thermal analysis of the copolymer of PBT-PGA showed a slight depression in the melting temperature for the higher molecular weight products. The low molecular weight copolymers showed a greater depression in the melting temperature. The heat of fusion (a measure of the % crystallinity) of the copolymer increased and then decreased over a period of 50 to 55 days for the samples maintained at 60° C.

The viscometric studies in Tables 1, 2 and 3 indicate a significant decrease in the intrinsic viscosity (indicative of a change in molecular weight of the copolymer and also of a change in the physical properties for the polymer) of copolymers made in accordance with the present invention when hydrolyzed in water.

              TABLE 1______________________________________(PBT-PGA 95:5)Intrinsic ViscosityDays    3° C.  33° C.                         50° C.______________________________________ 3                    0.44    0.48 4      0.4112                    0.42    0.4015      0.4016                    0.41    0.3920      0.40                  0.3524                            0.3440                            0.3450      0.36          0.3655      0.3962                    0.3577                    0.29______________________________________

              TABLE 2______________________________________(PBT-PGA 90:10)Intrinsic ViscosityDays    3° C.  33° C.                         50° C.______________________________________ 0                            0.55 4      0.39                  0.38 6                    0.4112      0.35                  0.3616                    0.40    0.3320      0.35                  0.3040                            0.2750                    0.2755      0.3862      0.39          0.2872      0.3877                    0.29______________________________________

              TABLE 3______________________________________(PBT-PO)Intrinsic ViscosityDays     99:1          90:10  70:30______________________________________0        0.99          1.09   1.215        0.98          0.41   0.1110       0.86                 0.09______________________________________

The intrinsic viscosities of the samples, as tabulated in Tables 1 and 2 for PBT-PGA copolymer and in Table 3 for PBT-PO copolymer, decreased at different rates depending upon the temperature at which they were maintained. The decrease in intrinsic viscosity implies that the copolymeric material degrades to lower molecular weight with water. These data indicate that the viscosity falls at a faster rate at higher temperature and that the rate of degradation is increased as the weight percent of the PGA is increased.

Fiber formation utilizing both polyglycolic and polyoxalate as the random hydrolyzable segments in the polyester co-polymer backbone have been successfully carried out using a single screw laboratory scale extruder.

Although the polymeric ratio is a matter of choice depending upon the physical characteristics of the final copolymer desired, the copolymers of the present invention may also be manufactured as a concentrate having the aromatic polyester moiety as a minor proportion (by weight percent), and the hydrodegradable segments as the major proportion. For example, the concentrate can easily be prepared and stored as a 5:95 polyester: hydrolyzable moiety copolymer. Prior to the manufacture of a product utilizing the random copolymers of the present invention, the concentrate would have the bulk of the polyester material added to it to arrive at the desired polymeric concentration. For example, by adding additional bulk PBT polyester to a 5:95 PBT:PGA concentrate, the final copolymer prepared from this material can be adjusted to have the 95:5 ratio of the copolymer in Table 1. Of course, present polymeric compositions are considered to be concentrates in accordance to the present invention, and the addition of a hydrolyzable moiety to these concentrates to achieve hydrodegradable segments.

Thus, while we have illustrated and described the preferred embodiments of our invention, it is to be understood that this invention is capable of variation and modification, and we therefore do not wish to be limited to the precise terms set forth, but desire to avail ourselves of such changes and alterations which may be made for adapting the invention to various usages and conditions. Accordingly, such changes and alterations are properly intended to be within the purview of the following claims.

Having thus described our invention and the manner and process of making and using it in such full, clear, concise and exact terms so as to enable any person skilled in the art to which it pertains, or with which it is most nearly connected, to make and use the same.

Each of the publications and patents, referred to hereinabove, are expressly incorporated herein by reference in their entirety.

Claims (2)

What is claimed is:
1. A hydrodegradable polyester copolymer consisting essentially of a substantially non-degradable aromatic polyester subunit and a hydrodegradable oxalate subunit and having the formula ##STR5## wherein R is selected from the group consisting of a straight or branched alkylene of 2 to 16 carbons in length, a polyether of the formula --[(CH2)n --O]x --(CH2)n --, or a mixture thereof, wherein n is a number from 2 to 16 and X is a number from 1 to 1000;
R2 is selected from the group consisting of a straight or branched alkylene of 2 to 16 carbons in length, a polyether of the formula --[(CH2)n --O]x --(CH2)n --, or a mixture thereof, wherein n is a number from 2 to 16 and X is a number from 1 to 1000, said hydrolyzable oxalate subunit being randomly distributed in, and comprising 5-30 weight percent of said copolymer, the balance of said copolymer being said aromatic polyester subunit, and said copolymer exhibiting a significant decrease in intrinsic viscosity when hydrolyzed in water at a temperature of about 50° C. for about 3-4 days.
2. As an article of manufacture, the copolyester of claim 1 in the form of fishing line.
US08485162 1991-09-24 1995-06-07 Hydrodegradable polyesters Expired - Fee Related US5594076A (en)

Priority Applications (4)

Application Number Priority Date Filing Date Title
US76465291 true 1991-09-24 1991-09-24
US6076393 true 1993-05-11 1993-05-11
US13503593 true 1993-10-12 1993-10-12
US08485162 US5594076A (en) 1991-09-24 1995-06-07 Hydrodegradable polyesters

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
US08485162 US5594076A (en) 1991-09-24 1995-06-07 Hydrodegradable polyesters

Related Parent Applications (2)

Application Number Title Priority Date Filing Date
US76465291 Continuation-In-Part 1991-09-24 1991-09-24
US13503593 Continuation 1993-10-12 1993-10-12

Publications (1)

Publication Number Publication Date
US5594076A true US5594076A (en) 1997-01-14

Family

ID=27369901

Family Applications (1)

Application Number Title Priority Date Filing Date
US08485162 Expired - Fee Related US5594076A (en) 1991-09-24 1995-06-07 Hydrodegradable polyesters

Country Status (1)

Country Link
US (1) US5594076A (en)

Cited By (20)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US5786408A (en) * 1995-06-22 1998-07-28 Daicel Chemical Industries, Ltd. Biodegradable polyester resin composition, and a biodegradable molded article
WO2001013819A2 (en) * 1999-08-24 2001-03-01 Absorbable Polymer Technologies, Inc. A method of making biodegradable polymeric implants
US6475618B1 (en) 2001-03-21 2002-11-05 Kimberly-Clark Worldwide, Inc. Compositions for enhanced thermal bonding
US20040024102A1 (en) * 2002-07-30 2004-02-05 Hayes Richard Allen Sulfonated aliphatic-aromatic polyetherester films, coatings, and laminates
US20050119696A1 (en) * 2003-12-02 2005-06-02 Walters Troy M. Braided suture
US20050119217A1 (en) * 2003-10-30 2005-06-02 Lacasse Eric Methods and reagents for the treatment of proliferative diseases
US20060113807A1 (en) * 2002-12-10 2006-06-01 Gerard Lefevre Dog excrement collector
US20070042446A1 (en) * 1995-08-04 2007-02-22 Korneluk Robert G Mammalian IAP gene family, primers, probes and detection methods
US20070049544A1 (en) * 2002-03-27 2007-03-01 Lacasse Eric Antisense IAP nucleobase oligomers and uses thereof
US20070088135A1 (en) * 2003-04-10 2007-04-19 Andreas Lednlein And Ute Ridder Blends with shape memory characteristics
US20070095957A1 (en) * 2003-11-21 2007-05-03 Kazuyuki Yamane Method of recycling laminated molding
US20070129787A1 (en) * 2005-12-01 2007-06-07 Bezwada Biomedical, Llc Difunctionalized aromatic compounds and polymers therefrom
US20070142316A1 (en) * 2000-09-28 2007-06-21 Korneluk Robert G Antisense IAP oligonucleotides and uses thereof
US20070241483A1 (en) * 2004-06-09 2007-10-18 Novamont S.P.A. Process for The Production of Biodegradable Films Having Improved Mechanical Properties
US20090142334A1 (en) * 1997-02-13 2009-06-04 Aegera Therpeutics, Inc. DETECTION AND MODULATION OF IAPs AND NAIP FOR THE DIAGNOSIS AND TREATMENT OF PROLIFERATIVE DISEASE
US20090249681A1 (en) * 2008-02-28 2009-10-08 College Of William And Mary Crab Trap with Degradable Cull Ring Panel
US20090288335A1 (en) * 2008-05-23 2009-11-26 Whitmire Micro-Gen Research Laboratories, Inc. Pest control system and method
US20100186283A1 (en) * 2008-02-28 2010-07-29 College Of William And Mary Fishing Trap with Degradable Cull Ring Panel
US20140157649A1 (en) * 2012-02-23 2014-06-12 College Of William And Mary Degradable Identification Component
US8938908B2 (en) 2008-02-28 2015-01-27 College Of William And Mary Fishing gear with degradable component

Citations (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3413379A (en) * 1964-01-17 1968-11-26 Chemische Werke Witten Gmbh Process for the preparation of linear thermoplastic mixed polyesters having softening points above 100deg.
US4032993A (en) * 1974-06-28 1977-07-05 Rhone-Poulenc Industries Bioresorbable surgical articles
US4139525A (en) * 1977-08-22 1979-02-13 Chevron Research Company Flexible glycolic acid terpolymers
US4311824A (en) * 1978-10-05 1982-01-19 Rhone-Poulenc Industries Thermotropic alkylaromatic copolyesters
US4419507A (en) * 1982-01-25 1983-12-06 Eastman Kodak Company Copolyester adhesives
US4532928A (en) * 1983-01-20 1985-08-06 Ethicon, Inc. Surgical sutures made from absorbable polymers of substituted benzoic acid

Patent Citations (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3413379A (en) * 1964-01-17 1968-11-26 Chemische Werke Witten Gmbh Process for the preparation of linear thermoplastic mixed polyesters having softening points above 100deg.
US4032993A (en) * 1974-06-28 1977-07-05 Rhone-Poulenc Industries Bioresorbable surgical articles
US4139525A (en) * 1977-08-22 1979-02-13 Chevron Research Company Flexible glycolic acid terpolymers
US4311824A (en) * 1978-10-05 1982-01-19 Rhone-Poulenc Industries Thermotropic alkylaromatic copolyesters
US4419507A (en) * 1982-01-25 1983-12-06 Eastman Kodak Company Copolyester adhesives
US4532928A (en) * 1983-01-20 1985-08-06 Ethicon, Inc. Surgical sutures made from absorbable polymers of substituted benzoic acid

Cited By (34)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US5786408A (en) * 1995-06-22 1998-07-28 Daicel Chemical Industries, Ltd. Biodegradable polyester resin composition, and a biodegradable molded article
US20070042446A1 (en) * 1995-08-04 2007-02-22 Korneluk Robert G Mammalian IAP gene family, primers, probes and detection methods
US7776552B2 (en) 1995-08-04 2010-08-17 University Of Ottawa Mammalian IAP gene family, primers, probes and detection methods
US20090142334A1 (en) * 1997-02-13 2009-06-04 Aegera Therpeutics, Inc. DETECTION AND MODULATION OF IAPs AND NAIP FOR THE DIAGNOSIS AND TREATMENT OF PROLIFERATIVE DISEASE
WO2001013819A2 (en) * 1999-08-24 2001-03-01 Absorbable Polymer Technologies, Inc. A method of making biodegradable polymeric implants
WO2001013819A3 (en) * 1999-08-24 2001-09-13 Absorbable Polymer Technologie A method of making biodegradable polymeric implants
US20070142316A1 (en) * 2000-09-28 2007-06-21 Korneluk Robert G Antisense IAP oligonucleotides and uses thereof
US6946195B2 (en) 2001-03-21 2005-09-20 Kimberly-Clark Worldwide, Inc. Compositions for enhanced thermal bonding
US6475618B1 (en) 2001-03-21 2002-11-05 Kimberly-Clark Worldwide, Inc. Compositions for enhanced thermal bonding
US7638497B2 (en) 2002-03-27 2009-12-29 Aegera Therapeutics, Inc. Antisense IAP nucleobase oligomers and uses thereof
US20070049544A1 (en) * 2002-03-27 2007-03-01 Lacasse Eric Antisense IAP nucleobase oligomers and uses thereof
US7638620B2 (en) 2002-03-27 2009-12-29 Aegera Therapeutics, Inc. Antisense IAP nucleobase oligomers and uses thereof
US20040024102A1 (en) * 2002-07-30 2004-02-05 Hayes Richard Allen Sulfonated aliphatic-aromatic polyetherester films, coatings, and laminates
US7204532B2 (en) * 2002-12-10 2007-04-17 Lefevre Gerard Dog excrement collector
US20060113807A1 (en) * 2002-12-10 2006-06-01 Gerard Lefevre Dog excrement collector
US20070088135A1 (en) * 2003-04-10 2007-04-19 Andreas Lednlein And Ute Ridder Blends with shape memory characteristics
US20050119217A1 (en) * 2003-10-30 2005-06-02 Lacasse Eric Methods and reagents for the treatment of proliferative diseases
US8012944B2 (en) 2003-10-30 2011-09-06 Pharmascience Inc. Method for treating cancer using IAP antisense oligomer and chemotherapeutic agent
US8119699B2 (en) * 2003-11-21 2012-02-21 Kureha Corporation Method of recycling laminated molding
US20070095957A1 (en) * 2003-11-21 2007-05-03 Kazuyuki Yamane Method of recycling laminated molding
US20050119696A1 (en) * 2003-12-02 2005-06-02 Walters Troy M. Braided suture
US20070241483A1 (en) * 2004-06-09 2007-10-18 Novamont S.P.A. Process for The Production of Biodegradable Films Having Improved Mechanical Properties
US8007526B2 (en) * 2005-12-01 2011-08-30 Bezwada Biomedical, Llc Difunctionalized aromatic compounds and polymers therefrom
US20070129787A1 (en) * 2005-12-01 2007-06-07 Bezwada Biomedical, Llc Difunctionalized aromatic compounds and polymers therefrom
US20100186283A1 (en) * 2008-02-28 2010-07-29 College Of William And Mary Fishing Trap with Degradable Cull Ring Panel
US20090249681A1 (en) * 2008-02-28 2009-10-08 College Of William And Mary Crab Trap with Degradable Cull Ring Panel
US8938908B2 (en) 2008-02-28 2015-01-27 College Of William And Mary Fishing gear with degradable component
US8375623B2 (en) * 2008-02-28 2013-02-19 College Of William And Mary Fishing trap with degradable cull ring panel
US20090288335A1 (en) * 2008-05-23 2009-11-26 Whitmire Micro-Gen Research Laboratories, Inc. Pest control system and method
US8215052B2 (en) * 2008-05-23 2012-07-10 Basf Corporation Pest control system and method
US20110239528A1 (en) * 2008-05-23 2011-10-06 Basf Corporation Pest control system and method
US7987630B2 (en) * 2008-05-23 2011-08-02 Basf Corporation Pest control system and method
US20140157649A1 (en) * 2012-02-23 2014-06-12 College Of William And Mary Degradable Identification Component
US9520074B2 (en) * 2012-02-23 2016-12-13 College Of William And Mary Degradable identification component

Similar Documents

Publication Publication Date Title
US5883199A (en) Polyactic acid-based blends
US6245844B1 (en) Nucleating agent for polyesters
US4132707A (en) Preparation of branched poly(alkylene terephthalates)
US4469851A (en) Molding composition
US6297347B1 (en) Biodegradable polymers, the production thereof and the use thereof for producing biodegradable moldings
Södergård et al. Properties of lactic acid based polymers and their correlation with composition
US4259478A (en) Process for preparing high molecular weight copolyesters
US5618911A (en) Polymer containing lactic acid as its constituting unit and method for producing the same
US5594068A (en) Cellulose ester blends
US5646208A (en) Transesterification-inhibited polyester melt blend compositions having modified thermal properties
US4205158A (en) Copolyetherester based on ethylene oxide-capped poly(propylene oxide) glycol and branching agent
US6818730B2 (en) Process to produce polyesters which incorporate isosorbide
US6018004A (en) Biodegradable polymers, preparation thereof and use thereof for producing biodegradable moldings
US6046248A (en) Biodegradable polymers, the preparation thereof and the use thereof for producing biodegradable moldings
US6323307B1 (en) Degradation control of environmentally degradable disposable materials
Witt et al. Biodegradation behavior and material properties of aliphatic/aromatic polyesters of commercial importance
US4897453A (en) Compatible blends of polyester-ethers and polycarbonates
US4238600A (en) Copolyesters derived from terephthalic acid, phenylhydroquinone and t-butylhydroquinone
Nikolic et al. Synthesis and characterization of biodegradable poly (butylene succinate-co-butylene adipate) s
US5180765A (en) Biodegradable packaging thermoplastics from lactides
US20040019178A1 (en) Enzyme-catalyzed polycondensations
US6521717B1 (en) Biodegradable polyester resin composition and its use
Witt et al. Synthesis, properties and biodegradability of polyesters based on 1, 3‐propanediol
US20040116619A1 (en) Polyester resins with improved properties
US5216050A (en) Blends of polyactic acid

Legal Events

Date Code Title Description
FPAY Fee payment

Year of fee payment: 4

FPAY Fee payment

Year of fee payment: 8

REMI Maintenance fee reminder mailed
LAPS Lapse for failure to pay maintenance fees
FP Expired due to failure to pay maintenance fee

Effective date: 20090114